Engine starter



Nov. 12, 1940. I i J. w. FITZGERALD Q 2,221,085

ENGINE STARTE R Fil ed Marsh '30, 1940 2 23 Jul-1n w. Firz GeraldPatented Nov. 12,1940

UNlTED STATES ENGINE STARTER JohnW. Fits Gerald, Milwaukee, Wis,asslgnor to Briggs & Stratton Corporation, Milwaukee,

' Win, a corporation of Delaware Application March so, 1940, Serial No.327,059 8 Claims. 74 -1) This invention relates to engine starters andthe like the copending applicationof John W.

Fitz Gerald, Serial No. 327,058, filed Mar. 30, 1940,

has, as its broad general object, the provision of I means for holdingthe pinion of a so-called automatic type starter in mesh with the enginering gear until the engine has been fully started.

As explained at length in said copendlng application, the automatic typeof engine starter in 2 which the pinion is automatically propelled intomesh with the ring gear and automatically retracted has the disadvantageof de-meshing substantially immediately after 'the first explosion inthe engineso that in engines which start hard, the starting cycle mustbe repeated several times.

In the manual type of engine starter in which the pinion is manuallymoved into mesh with the ring gear and held in mesh as long as thestarter pedal is depressed, there is the danger that the overrunningclutch which is provided to allow the pinion to spin when the enginestarts, often sticks I and as a consequence, the starter armature isrevolved at speeds apt to cause damage to the armature.

This invention, like that forming the subject matter of the aforesaidcopending application, therefore, contemplates the provision of meansfor preventing retraction of the pinion in an automatic type of starteruntil the engine is actually operating under its own power but withoutdanger to the starter motor.

The specific purpose of the present invention is to provide meansforcontrolling pinion retraction from some function of the engine.

With the above and otherobjects in view, whic will appear as thedescription proceeds,'this inventionresides in the novel construction,combination and arrangement of parts substantially as hereinafterdescribed, and more particularly 40 defined by the appended claims, itbeing understood that such changes in the precise embodiment of thehereindisclosed invention may be made as come within the scope of theclaims.

The accompanying drawing illustrates several ll complete examples of thephysical embodiment of the invention, constructed in accordance with thebest modes; so far devised for the practical application of theprinciples thereof, and in which:

50 Figure 1 is a side view of an engine starter embodying thisinvention, said view showing the pinion in mesh with the ring gear;

Figure 2 is a side view of part of the starter mechanism illustrating amodified form of pinion control; and

Figures 3 and 4 are views similar to Figure 2 illustrating two othermodified embodiments of the invention.

Referring now particularly to the accompanying drawing, in which likenumerals indicate like parts, the numeral 5 designates the ring gear ofan engine to be started by the starter mechanism, indicated generally bythe numeral 6. The starter mechanism comprises a pinion I mounted tomove longitudinally along a. motor driven power shaft 1' to and from anoperative position meshing with the ring gear.

The entire starter mechanism is mounted as a unit on the shaft I.Besides the pinion I, it comprises a pinion actuating screw 8 coupled tothe power shaft through a torsionally and endwise resilient coupling,indicated generally by the numeral l0.

The specific construction of the coupling forms no part of thisinvention and may be like that iilustrated in the John W. Fitz GeraldReissue Patent No. 20,686, issued April 5, 1938, for Engine starter;

The actuating screw 8 is externally threaded and is received in aninternally threaded sleeve l I, extended from the pinion. Hence, uponrelative rotation between the screw and the pinion, the pinion ispropelled into mesh with the ring gear or retracted, depending upon thedirection of the speed diflerential.

The objectives of this invention may be accomplished inseveral ways andin the method employed in the structure shown inFigure 1, a detent orlatch pin I2 is arranged to drop into an annular groove I! in the pinionsleeve when the pinion is fully meshed with the ring gear.

The pin I2 is constrained to axial motion and held agninst displacementin any suitable manner so that when it engages in the groove lI,as shownin Figure 1, retraction of the pinion is prevented. Hence, by makingwithdrawal of the pin I! dependent upon some function of the engine infull operation, the starter can be held in mesh until the engine hasbeen properly started. One such function of the engine is intakemanifold suction.

To utilize this function of the engine, the pin l2 has a piston I 4connected thereto which reciprocates in a cylinder it The cylinderwisconnected through a duct 16 to the intake manifold. Consequently, whenthe'engine begins to operate under its own power, the suction inthe.intake manifold becomes strong enoughto lift the piston andconsequently, th'elockingpin to inoperative position.

f responsive to a source of While gravity may be depended upon to engagethe pin in the groove, if desired, a light spring I! may be interposedbetween the piston and the head of the cylinder. I

Another engine function which is readily adaptable to control of thepinion is oil pressure. and in Figure 2 one manner of utilizing oilpressure to lift the pin l2 out of the groove is illustrated. As hereshown, the cylinder I! may be connected through a duct l8 with the 011line on the pressure side of the pump so that oil pressure lifts the thegroove.

To prevent dashpot action, closes the open end of the cylinder withan'air bleed.

The output of the generator also may be used to lift the locking pin outof the groove, and one simple manner of utilizing this function of theengine is illustrated in Figure 3. For this purpose, it is onlynecessaryto provide the pin with a solenoid plunger 20 which moves axially into asolenoid coil 2| upon energization of the coil.

The coil may be connected with the electric system of the engine in anymanner as long as the energizing current is dependent upon operation ofthe generator. With this form of the invention, it is preferable to havethe locking pin l2 formed of nonmagnetic metal.

Still another manner of controlling the pinion from the engine is toprovide a vane 22 pivoted, as shown in Figure 4, behind the cooling thecap l8 which is provided fan 23 so that the blast from the fan tilts thevane about its pivotal mounting. A suitable system of levers 24 utilizesthe motion thus produced to lift'the locking pin out of the groove l3.

From the foregoing description taken in connection with the accompanyingdrawing, it will be readily apparent to those skilled in the art, thatthis invention provides an exceptionally simple manner of holding thestarter in mesh until thev engine actually begins to operate under itsown power.

What I claim as my invention is:

1. An engine starter of the type having a pinion automatically movableinto mesh with the ring gear of an engine to be started andautomatically retractable upon starting of the engine: characterized bythe provision of releasable latch means for holding the pinion in mesh;and means responsive to a source of energy remote from the starter forreleasing said latch means.

2. In a starter for internal combustion engines, the combination of: anengine carried gear; a pinion; means for automatically moving' thepinion into mesh with the engine gear and for driving the engine gear toeffect cranking of the engine and for automatically retracting thepinion from mesh with the engine gear upon starting of the engine;releasable means for holding the pinion in mesh with the engine gear topreclude premature de-meshlng; and means energy remote from the starterand rendered operative solely as a consequence to the engine operatingunder its own'power for disabling said holding means to free the pinionfor retraction.

3. In an engine starter: a pinion movable to and. from an operativeposition; means for automatically projecting the pinion to its operativeposition and for automatically retracting the piston ll to raise thelocking pin out of nular shoulder carried by pinion from its operativeposition; means for holding the pinion in mesh with the engine flywheel;and means wholly independent of the starter for disabling said holdingmeansto free the pinion for retraction.

4. In an engine starter: an engine driving member movable to and from anoperative position; means for automatically propelling the enginedriving member to its operative position and for automaticallyretracting the engine driving member from its operative position; ananthe engine driving member; a holding member engageable with saidshoulder to hold the engine driving member in operative position whileenabling free 'rotation' thereof; and means responsive to a force whollyoutside the starter for moving said holding member to an inactiveposition freeing the engine driving member for retraction.

5. In a starter for internal combustion engines having a ring gear: apinion movable to and from mesh with the ring gear; means forautomatically propelling the pinion into mesh with the ring gear, forturning the pinion to drive the ring gear and crank the engine and forautomatically retracting the pinion out of mesh; an annular shoulder onthe pinion; a holding mem ber engageable with said shoulder to hold thepinion in mesh with the ring gear; and means responsive to 51. source ofenergy remote from the starter for moving said holding member to aninoperative position freeing the pinion for retraction.

6. In a starter for internal combustion engines; an engine drivingmember movable to and from an operative position engaging an engine partto effect cranking of the engine; means for automatically propelling theengine driving member to its operative position and for automaticallyretracting the same from its operative position; a holding member forholding the engine driving member in engagement with the engine part;and means responsive to enginesuction for moving said holding member toan inoperative position.

'7. In a starter for internal combustion engines: an engine drivingmember movable to and I from an operative position engaging 'an enginepart to eiIect cranking of the engine; means for automaticallypropelling the engine driving member to its operative position and forautomatically retracting the same from its operative position; a holdingmember for holding the engine driving member in engagement with theengine part; and means responsive to pressure in the oil line of theengine for moving said holding member to. an inoperative position.

8. In a starter for internal combustion engines; an engine drivingmember movable to and from an operative position engaging an engine partto effect cranking of the engine; means for automatically propelling theengine driving member to its operative position and for automaticallyretracting the same from its operative position; a holding member forholding the engine driving member in engagement with the engine part;and electromagnetic means adapted to be energized from the generator ofthe engine to move the holding member to an inoperative position.

JOHN W. FITZ GERALD.

